Dell SonicWALL Firewall Appliance WAN and LAN Configuration

Running inside a
SonicWALL device is the SonicOS operating system, which is responsible for
application and traffic management of organisation’s network infrastructure.
Below, we shall take a closer look at out of the box configuration of the
firewall.

Once the device unboxed,
you’ll find a power adapter cable as well as an ethernet cable in the package.
Assemble the adapter depending on which country you reside (UK or USA), then
plug the ethernet cable into the X0 port labelled LAN with the other end of
that cable plugging into the ethernet port on your laptop. Find an image of the
rear of the device below. Notice X0 for LAN and X1 for WAN.

To be able to access the
SonicWALL interface, you’ll need to check the IPv4 configuration on your
network card to ensure its set to acquire IP addresses automatically. In some
instances where the device has already been configured with an IP address such
as 10.10.0.25, you will need to change your network card address to match the
IP subnet of the firewall to be able to access it.

For example, to access an
already configured device with an address such as above, you’ll need to set
your network card to 10.10.0.50 to give you access to the device interface.

If you are not familiar with
how to do this, access Control Panel > Network and Internet > Network and
Sharing Centre > Change adapter settings > Right click adapter > Click
Properties.

The Ethernet Properties dialog
box should pop up as above. Highlight Internet Protocol Version 4 (TCP/IPv4)
and click Properties. We can now
configure the network card to match the subnet of the new SonicWALL, for which
I set 192.168.168.10 to demonstrate the config process.

Make sure to set the default
gateway to SonicWALL’s default address 192.168.168.168 and click OK to finish.

1.SonicWALL
> Network > Interfaces

Launching your browser, access
http://192.168.168.168
and once the log in screen loads, type in the SonicWALL default credentials
username: admin Password: password to be presented with the
dashboard. Expand the Network tree and Click on Interfaces to see the screen
displayed above.

Depending on the model of
SonicWALL you’re working on, you may see X0 to X5 or more which we’re going to
use to configure our WAN and LAN interfaces, so our internal network can gain
access to the wide area internet services.

2.Configuring Static IP WAN on SonicWALL Interface X1

To perform this task, you will
need to purchase an internet service package from an ISP. This could be an ADSL
or Fibre leased line with parameters such as Public IP address, subnet mask,
default gateway, DNS servers and usable IP addresses. It should look like these
fictitious parameters below;

-LAN
Subnet: 62.319.68.89/30

-Subnet
Mask:255.255.255.252

-Network:62.319.68.89

-Default
Gateway:62.319.68.90

-Usable
IP:62.319.68.91

-Broadcast:62.319.68.92

-DNS
Server 1:88.215.81.255

-DNS
Server 2:88.215.83.255

Since this article will walk
you through setting up WAN and LAN for internet connection, we’ll be focusing
our attention on X1 = WAN and X0 = LAN interfaces and configure them to gain
access to the internet.

Click on the configure radio
button next to Default WAN and begin populating the details you received from
your ISP. Set Zone to WAN, IP Assignment to Static and DNS Server 3 to 8.8.8.8

If you are satisfied the
details are correct, click on Advanced to inspect further settings WAN traffic
transmission settings.

Some ISPs may provision your internet connection as PPPoE with a username and password. The SonicWALL device can handle connections of this type by your input in the IP Assignment field.

Once credentials are populated, you can click OK to finish. Want to access the device remotely over public IP address? simply tick the HTTPS radio button next to Management. Be sure to set a very complex admin password on the device if this function is enabled.

4.Configuring
LAN on SonicWALL Interface X0

Settings on this interface affect
all equipment sitting behind the firewall in your organisation. In a production
environment, an ethernet cable from this port connects to your switch and
splits the internet signal to all IP enabled devices including servers,
workstations and printers.

To configure this, you would
have to decide which IP address system you want your network to have. For this
demonstration, we’ll be using 192.168.50.1 with subnet mask 255.255.255.0

Just as we did above, click
the Configure radio button next to Default LAN and populate the details.

Bear in mind at this point
that once you click OK, the status
of the SonicWALL will change, and you can no longer access the device on the
default IP address. Open your network card configuration page again and set it
to receive IP addresses via DHCP.

If your ISP settings are
correct, you should see 1 Gbps Full Duplex status on both interfaces. Test the
connection by visiting any of your favourite sites such as www.YouTube.com

5.Changing
Default Admin Password

For obvious security reasons,
it is advisable to change the device access IP and password of your SonicWALL,
since these details hold true for all units shipped out all over the world.

As we don’t want to give hackers
a great field day breaking into our network, changing the LAN IP address like
we did above, blocks one layer of vulnerability of the firewall.

Navigate System Setup >
Appliance > Base Settings. A lot of settings are available from this window,
but you can go ahead and change your password. To make it more secure, change
the main Administrator name to something more specific, a name that is harder
to guess.

Further advanced security lock-down
features will be explored in later topics.

6.Managing
DHCP Server on SonicWALL

It is important to note at
this point that, DHCP service can be controlled from the SonicWALL or from your
server, if you have one installed on the network.

Navigate to Network > DHCP
Server to open the interface as shown below;

Tick the radio button to enable
DHCPv4 Server and click Accept to
save the settings. This server will now be responsible for distributing IP
addresses, subnet masks, gateway addresses, and DNS server addresses to your
network clients.

You have further options to
control the number of IP addresses, and lease times for those addresses to
expire on the client computers.

On the same interface, click Dynamic > ADD to configure these settings > Click OK.

In the example above, I have
set my DHCP scope between 192.168.50.2 – 192.168.50.254. The number of
addresses allocated to your client machines depends entirely on you but, it is
good industry practice to limit the scope to the number of machines in your
environment, aiding with easier security audits and identification of bad or
conflicting IP addresses.

All devices currently
connected to the firewall can be viewed in the Current DHCPv4 Leases window.

A good
industry practice is to back up your SonicWALL device configuration to a file,
to aid faster disaster recovery times. Refer to our previous article for steps on how to do this task.

You can sit the test at
the cost of about $400. Your company stands to benefit from huge partnership
discounts on SonicWALL products if one network engineer in the business gains
these certifications.

Dell SonicWALL Appliance Operating System
Overview

Getting your hands on one of
the SonicWALL devices like TZ300 could set you back about £780, a great price
for small to medium size businesses to implement network security policies.

For the purposes of learning
however, an online live demo version of the device operating system interface
is available for Free from SonicWALL

Final
Thoughts

We hope
you found this article useful as a guide to configure Wide Area Network (WAN), Local
Area Network (LAN), DHCP server and securing your device by changing the admin password.
SonicWALL represents a cost-effective way to deploy security solutions for Small
to Medium Enterprises (SMEs). Head over to SonicWALL website for
more information.

Join us
again as we explore further advanced configurations such as VPN, port
forwarding and setting up a failover load balancing for resilience.